A modern ski shoe supports the forward position of the skier during downhill skiing by permitting the shaft of the shoe to assume an inclined position in a skiing direction relative to the shell and thus relative to the base member of the ski shoe. Designs are known, in which this forward movement to the inclined position occurs against an adjustable resistance. The raised shell part, which is surrounded by the shaft of the shoe and which itself elastically surrounds the leg of the user like a sleeve, has for this purpose an upwardly open U-shaped slot above the heel. The shaft of the shoe lies in its erect position approximately concentric with respect to the raised shell part. When the skier moves into the forward position, the shaft of the shoe assumes an inclined position relative to the shell and also relative to the raised shell part, which inclined position results in the shaft of the shoe resting with its inner surface on the outer surface of the raised shell part and applying a pressure onto the outer surface. The elastic raised shell part yields, especially since the form stability is weakened by the vertical slot. With an increasing inclined position of the shaft of the shoe, the shaft of the shoe compresses the slot due to its roundness, which has a width of, for example, 1 cm, until the longitudinal edges defining the slot contact one another near the upper edge of the shell. Thus the slot opens elastically during relief and closes under the pressure of the forwardly inclined shaft of the shoe. Aside from the material of the shell, the length and the geometry of the slot are a measure for the resistance, which is applied against the forward movement of the shaft of the shoe by the shell.
From U.S. Pat. No. 3,848,347 and U.S. Pat. No. 3,936,959 it is known to close a slot on a ski shoe by a movable clamp, which slot allows freedom of movement in one direction. Depending on the position of the clamp the slot is more or less effective.
EP-A2 350 023 discloses a ski shoe with a vertical slot in the heel area of the shell, in which a carriage is longitudinally movably arranged in the slot as a spacer, which can be moved on a spindle. The carriage rests on both sides on the walls of the slot and prevents or makes difficult the narrowing of the width of the gap of the slot depending on its elevational position in the slot. The spindle extends over and parallel to the entire length of the slot, and can be rotated by a knurling tool for effecting an elevational adjustment of the carriage in the slot. The higher the carriage is adjusted in the slot, the greater is the resistance against the forward movement of the shaft of the shoe. A similar design is furthermore known, in which the slot in the shell has a downwardly diverging edging and in which the spacer or rather a spreader is elevationally adjustable on a vertical spindle. These long threaded spindles in the heel area of the ski shoe stiffen the shaft of the shoe in an undesired manner and are highly stressed. When they bend, the result is that the elevational adjustment no longer functions and the spacer or rather the spreader jams up. Moreover, adjustment by means of an adjusting device in the heel area is unfavorable and is difficult to reach with the hands when the ski is attached.